Change slot position to a short to keep object size below 32 bytes

Author: gbrail

rhino/src/main/java/org/mozilla/javascript/OrderedSlotMap.java

@@ -228,7 +228,8 @@ private void insertNewSlot(Slot newSlot) {
             System.arraycopy(orderedSlots, 0, newOrderedSlots, 0, orderedCount);
             orderedSlots = newOrderedSlots;
         }
-        newSlot.orderedPos = orderedCount;
+        assert orderedCount < Short.MAX_VALUE;
+        newSlot.orderedPos = (short)orderedCount;
         orderedSlots[orderedCount++] = newSlot;
         addKnownAbsentSlot(slots, newSlot);
     }

rhino/src/main/java/org/mozilla/javascript/Slot.java

@@ -18,7 +18,7 @@ public class Slot implements Serializable {
     Object value;
     transient Slot next; // next in hash table bucket for EmbeddedSlotMap only
     transient Slot orderedNext; // next in linked list for EmbeddedSlotMap only
-    transient int orderedPos; // Position in the array for OrderedSlotMap only
+    transient short orderedPos; // Position in the array for OrderedSlotMap only
 
     Slot(Object name, int index, int attributes) {
         this.name = name;

rhino/src/main/java/org/mozilla/javascript/SlotMapOwner.java

@@ -10,6 +10,11 @@
 public abstract class SlotMapOwner {
     private static final long serialVersionUID = 1L;
 
+    /**
+     * At this size, we switch from various cleverly optimized maps to an implementation based on
+     * java.util.HashMap, which is collision-resistant. This must be less than Short.MAX_VALUE or
+     * OrderedSlotMap will break.
+     */
     static final int LARGE_HASH_SIZE = 2000;
 
     static final SlotMap EMPTY_SLOT_MAP = new EmptySlotMap();